What are the main interference sources of the two power system
Power system electromagnetic environment consists of one or two devices, of which there are a variety of electromagnetic disturbance and interaction, the current electric power system is developing towards higher voltage, higher capacity, power network is more intensive and more complex systems, more advanced equipment to the direction of development, to guide electromagnetic disturbance of power system more serious and complicated. On the other hand, the advanced power systems using more advanced automation and other electronic and computer control, measurement, communication and protection system, and solid state electronic based advanced equipment and system tolerance electromagnetic disturbance ability is weaker, more susceptible to electromagnetic environment.
There are three kinds of electromagnetic interference in power system: electromagnetic interference between the primary equipment, the primary equipment and the secondary equipment, and between the two devices, and the electromagnetic interference between the two devices. According to the propagation path of electromagnetic disturbance, it can be divided into conduction coupling and radiation coupling. A line in the power system of switching operation, fault, lightning strikes, transient current and voltage and electromagnetic radiation line, enter the two loop through various coupling modes, these pathways are electromagnetic voltage transformer, capacitor voltage transformer, current transformer, coupling capacitor, high voltage bus and the two cable distribution between the capacitive and inductive coupling transmission way, also have a line to the surrounding space transient electromagnetic radiation energy, is two times the equipment or circuit receiving radiation coupling way.
The main source of disturbance in power system are: high voltage isolation switch and circuit breaker operation; short circuit and lightning system; partial discharge; two switch operation system; voltage load change and faults when the power grid has sag, interruption, unbalance, harmonics and frequency variation of power frequency and harmonic electric field and harassment; the magnetic field generator and transformer; transmission circuit in the surrounding electric field and magnetic field; high frequency conduction disturbance and radiation disturbance automation equipment, radio equipment; natural phenomena such as lightning, electrostatic discharge, geomagnetic disturbance and dry harassment pulse generated by nuclear power.
